<!-- 方案三：3D旋转 + 霓虹光效 -->
<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>登录 - 3D霓虹版</title>
    <style>
        * { margin: 0; padding: 0; box-sizing: border-box; }

        body {
            min-height: 100vh;
            background: #0f0f1a;
            display: flex;
            justify-content: center;
            align-items: center;
            perspective: 1000px;
        }

        .neon-box {
            position: relative;
            width: 400px;
            padding: 40px;
            background: #15151f;
            border-radius: 20px;
            transform-style: preserve-3d;
            transform: rotateX(0deg) rotateY(0deg);
            transition: all 0.3s;
            box-shadow: 0 0 30px rgba(127,90,240,0.2);
        }

        .neon-border {
            position: absolute;
            inset: 0;
            border-radius: 20px;
            padding: 2px;
            background: linear-gradient(45deg, #7f5af0, #2cb67d);
            -webkit-mask: 
                linear-gradient(#fff 0 0) content-box, 
                linear-gradient(#fff 0 0);
            mask: 
                linear-gradient(#fff 0 0) content-box, 
                linear-gradient(#fff 0 0);
            -webkit-mask-composite: xor;
            mask-composite: exclude;
        }

        .input-container {
            position: relative;
            margin: 30px 0;
        }

        input {
            width: 100%;
            padding: 15px 20px;
            background: #1a1a27;
            border: none;
            border-radius: 8px;
            color: white;
            font-size: 16px;
            transition: all 0.3s;
        }

        input:focus {
            outline: none;
            box-shadow: 0 0 10px rgba(127,90,240,0.3);
        }

        .neon-label {
            position: absolute;
            left: 20px;
            top: 50%;
            transform: translateY(-50%);
            color: #6c6c7a;
            pointer-events: none;
            transition: all 0.3s;
        }

        input:focus ~ .neon-label,
        input:valid ~ .neon-label {
            top: -10px;
            left: 10px;
            font-size: 12px;
            color: #7f5af0;
            text-shadow: 0 0 10px rgba(127,90,240,0.3);
        }

        .login-btn {
            width: 100%;
            padding: 15px;
            background: #7f5af0;
            border: none;
            border-radius: 8px;
            color: white;
            font-size: 16px;
            cursor: pointer;
            transition: all 0.3s;
            position: relative;
            overflow: hidden;
        }

        .login-btn:hover {
            background: #6d4bd1;
            box-shadow: 0 0 20px rgba(127,90,240,0.4);
        }
    </style>
</head>
<body>
    <div class="neon-box" id="neonBox">
        <div class="neon-border"></div>
        <h2 style="color: white; text-align: center; margin-bottom: 30px;">ADMIN LOGIN</h2>
        <div class="input-container">
            <input type="text" required>
            <span class="neon-label">Username</span>
        </div>
        <div class="input-container">
            <input type="password" required>
            <span class="neon-label">Password</span>
        </div>
        <button class="login-btn">SIGN IN</button>
    </div>

    <script>
        const box = document.getElementById('neonBox');
        document.addEventListener('mousemove', (e) => {
            const x = (window.innerWidth / 2 - e.pageX) / 20;
            const y = (window.innerHeight / 2 - e.pageY) / 20;
            box.style.transform = `rotateY(${x}deg) rotateX(${-y}deg)`;
        });
    </script>
</body>
</html>